Two types of semiconductor memory devices are volatile memory devices which lose their stored data content in the absence of power, and non-volatile memory devices which retain their stored data content in the absence of power.
A flash memory device, which is a type of non-volatile memory device, can be configured as a NOR type memory device and/or as a NAND type memory device. NOR type memory devices can have a relatively fast operational speed because they control each memory cell. However, because every two cells requires one contact, the NOR type memory device can have a relatively large size cell area. In contrast, a NAND type memory device controls a plurality of memory cells in one body by binding the memory cells with one string and, accordingly, can be configured for a high degree of integration.
The NAND type flash memory device includes a memory block and a page buffer block. The memory block includes a plurality of strings connected in parallel. Each string includes a plurality of cell transistors connected in serial, a string select transistor, and a ground select transistor, which are respectively disposed on both sides of the string. The page buffer block includes a plurality of page buffers. The page buffers transmit programming data and reading data between the memory block and a peripheral circuit. Bit lines are disposed to electrically connect page buffers to string select transistors for data transmission. The bit lines are divided into even bit lines and odd bit lines.
In a conventional NAND type flash memory device, bit lines in a memory block are arranged in an even/odd/even/odd bit line order. Accordingly, when a memory cell (hereinafter, referred to as an even cell) connected to an even bit line is programmed after programming a memory cell (hereinafter, referred to as an even cell) connected to an even bit line, the even cell has a relatively large influence from the odd cell. That is, since the odd cells are disposed on both ends of the even cells, coupling disturbance between adjacent cells can occur when a programming operation is performed, which may deteriorate the reliability and operational characteristics of the associated flash memory device.